Intermediates in the synthesis of cephalosporin compounds

ABSTRACT

Described herein are crystalline forms of a compound of formula (III − ), including toluene solvates off A TD-CLE, as well as processes for the preparation thereof and use thereof in the preparation of cephalosporin compounds such as ceftolozane. Provided herein is a crystalline form of a compound of formula (III − ): wherein X is CI, Br, or I; and R1 and R2 are each independently an oxygen protecting group; processes for making the crystalline form, and use of said form in the synthesis of antibacterial cephalosporins such as ceftolozane.

1. CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No.62/037,722, filed Aug. 15, 2014, which is incorporated herein byreference in its entirety.

2. TECHNICAL FIELD

This disclosure relates to the solid forms of an intermediate used inmanufacture of antibacterial cephalosporins such as ceftolozane.

3. BACKGROUND

Crystalline forms of compounds are often important when the compound isused in pharmaceutical applications. Compared with an amorphous solid,the solid physical properties of a crystalline compound can be markedlydifferent, affecting its suitability for pharmaceutical use.

For example, different forms of a crystalline compound, includingpolymorphs and solvates, can incorporate different types and/ordifferent amounts of impurities. Different solid forms of a compound canalso vary in chemical stability when exposed to different environmentalstressors such as heat and/or water.

Ceftolozane is a cephalosporin antibacterial agent, also referred to asCXA-101, FR264205, or by chemical names such as(6R,7R)-3-[(5-amino-4-{[(2-aminoethyl)carbamoyl]amino}-1-methyl-1H-pyrazol-2-ium-2-yl)methyl]-7-({(2Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-[(1-carboxy-1-methylethoxy)imino]acetyl}amino)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate,and7β-[(Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-{3-amino-4-[3-(2-aminoethyl)ureido]-2-methyl-1-pyrazolio}methyl-3-cephem-4-carboxylate.Ceftolozane sulfate is a pharmaceutically acceptable ceftolozane salt ofcompound (VI) (FIG. 1A) that can be formulated for intravenousadministration or infusion.

Ceftolozane can be obtained using methods described in U.S. Pat. Nos.7,129,232 and 7,192,943, as well as Toda et al., “Synthesis and SAR ofnovel parenteral anti-pseudomonal cephalosporins: Discovery ofFR264205,” Bioorganic & Medicinal Chemistry Letters, 18, 4849-4852(2008), each of which are incorporated herein by reference in theirentirety. An important intermediate in the known syntheses ofceftolozane is compound (III) (also referred to herein as “TATD-CLE”).

The published reaction to make compound (III) involves an isolationusing solvents such as, for example, diisopropyl ether. However, this isnot a preferred process because diisopropyl ether has significant vaporpressure at room temperature, is highly flammable and has the potentialto form peroxides upon storage.

Given the multi-step synthesis of ceftolozane and its commercialimportance, there is a need to develop new approaches for each of theindividual reaction steps in the synthesis of ceftolozane, such as thesynthesis of new forms of compound (III), to increase reaction yields,safety, and overall efficiency in the synthetic process.

4. SUMMARY

Provided herein is a crystalline form of a compound of formula (III′):

wherein X is Cl, Br, or I; and R¹ and R² are each independently anoxygen protecting group; processes for making the crystalline form, anduse of said form in the synthesis of antibacterial cephalosporins suchas ceftolozane.

In some embodiments, R¹ and R² are each independentlytert-butyldimethylsilyl, tert-butyl, 4-methoxybenzyl, 2-methoxybenzyl,or triphenylmethyl.

In some embodiments, the compound of formula (III′) has the structure ofcompound (III):

In some embodiments, the crystalline form is a solvate of an aromaticsolvent. In some embodiments, the aromatic solvent is toluene, xylene,ethylbenzene, benzene, cumene, or mixtures thereof. In some preferredembodiments, the solvate is a toluene solvate. In some embodiments, thecrystalline form has a 1:1 molar ratio of compound (III) to solvent.

In some embodiments, the crystalline form has an X-ray PowderDiffraction (XRPD) pattern comprising one or more characteristic peaksexpressed in degrees 2θ at about 6.1, about 12.1, about 13.1, about18.5, and about 24.3.

In some embodiments, the crystalline form has an X-ray PowderDiffraction (XRPD) pattern comprising one or more characteristic peaksexpressed in degrees 2θ at about 7.3, about 10.0, about 11.6, about17.7, and about 24.6.

In another aspect, provided herein is a process of preparing acrystalline form of a compound of formula (III′), comprising the step ofadmixing a non-crystalline form of a compound of formula (III′) and anaromatic solvent to form an admixture comprising the crystalline form ofa compound of formula (III′). In some embodiments, the process comprisescooling the admixture. In some embodiments, the process comprises thestep of isolating the crystalline form of a compound of formula (III′),e.g., compound (III).

In another aspect, provided herein is a process of preparing a compoundof formula (V″):

comprising admixing the crystalline form of a compound of formula (III′)with a compound of formula (IV′):

wherein R¹ and R² are each independently an oxygen protecting group; R⁵and R⁶ are each independently a nitrogen protecting group; and A^(⊖) isa pharmaceutically acceptable anion.

In some embodiments, R⁵ and R⁶ are each independently tert-butyl,tert-butoxycarbonyl, 2-trimethylsilylethoxycarbonyl, or triphenylmethyl.

In some embodiments, A^(⊖) is chloride, bromide, iodide, sulfate,bisulfate, toluenesulfonate, methanesulfonate, trifluoroacetate, ortrifluoromethanesulfonate.

In some embodiments, the compound of formula (V″) has the structure ofcompound (V):

and the compound of formula (IV′) has the structure of compound (IV):

In some embodiments, the process comprises the step of convertingcompound (V) to compound (VI):

comprising contacting compound (V) with trifluoroacetic acid.

In one aspect, provided herein is a toluene solvate of compound (III).

In one aspect, provided herein is a process for making a toluene solvateof compound (III) comprising the steps of admixing a non-crystallineform of compound (III) with an organic solvent comprising toluene toobtain the toluene solvate of compound (III).

In one aspect, provided herein is a process for making compound (V)comprising the step of admixing a toluene solvate of compound (III) withcompound (IV).

5. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is the chemical structure of ceftolozane sulfate.

FIG. 1B is an example synthetic scheme showing known methods ofceftolozane synthesis: see U.S. Pat. Nos. 7,129,232 and 7,192,943, aswell as Toda et al., “Synthesis and SAR of novel parenteralanti-pseudomonal cephalosporins: Discovery of FR264205,” Bioorganic &Medicinal Chemistry Letters, 18, 4849-4852 (2008).

FIG. 1C is a synthetic scheme for preparing a ceftolozane startingmaterial, a protected 5-amino-1-methylpyrazole, as disclosed in Toda etal.

FIG. 2 is a synthetic scheme for preparing a toluene solvate of compound(III) (TATD-CLE) from TATD-Ms (compound (Ib)) via reaction with ACLE(compound (II)).

FIG. 3A depicts a representative X-ray powder diffraction pattern of acrystalline toluene solvate of compound (III). The crystalline toluenesolvate characterized by the XRPD found in this figure is referred toherein as “compound (III) form 1” or “TATD-CLE form 1”.

FIG. 3B depicts a representative X-ray powder diffraction pattern of acrystalline form of compound (III). The crystalline form characterizedby the XRPD found in this figure is referred to herein as “compound(III) form 2” or “TATD-CLE form 2”.

FIG. 3C depicts variable temperature X-ray powder diffraction patterns(VT-XRPD) of the crystalline form of compound (III). The initialspectrum is of TATD-CLE form 1.

FIG. 3D depicts an exemplary variable temperature X-ray powderdiffraction pattern of the crystalline form of compound (III) at 110° C.obtained from heating a sample of TATD-CLE form 1.

FIG. 4 is a thermogravimetric analysis (TGA) curve for compound (III)form 1.

FIG. 5 is a differential scanning calorimetry (DSC) thermogram forcompound (III) form 1.

FIG. 6 shows the ¹H-nuclear magnetic resonance (NMR) spectrum of atoluene solvate of compound (III).

FIG. 7 shows the GC Chromatogram to analyze the toluene content of atoluene solvate of compound (III). The results showed the level oftoluene present in TATD-CLE form 1.

FIG. 8 shows the residual solvent content in a toluene solvate ofcompound (III). The results showed the level of toluene present inTATD-CLE form 1.

6. DETAILED DESCRIPTION 6.1. Definitions

As used herein, the following terms are intended to have the followingmeanings:

The term “substituted” refers to moieties having substituents replacinga hydrogen on one or more atoms on the indicated moiety. It will beunderstood that “substitution” or “substituted with” includes theimplicit proviso that such substitution is in accordance with permittedvalence of the substituted atom and the substituent, and that thesubstitution results in a stable compound, e.g., which does notspontaneously undergo transformation such as by rearrangement,cyclization, elimination, etc. As used herein, the term “substituted” iscontemplated to include all permissible substituents of organiccompounds. In a broad aspect, the permissible substituents includeacyclic and cyclic, branched and unbranched, carbocyclic andheterocyclic, aromatic and non-aromatic substituents of organiccompounds. The permissible substituents can be one or more and the sameor different for appropriate organic compounds. For purposes of thisinvention, the heteroatoms such as nitrogen may have hydrogensubstituents and/or any permissible substituents of organic compoundsdescribed herein which satisfy the valences of the heteroatoms.Substituents can include, for example, a halogen, a hydroxyl, a carbonyl(such as a carboxyl, an alkoxycarbonyl, a formyl, or an acyl), athiocarbonyl (such as a thioester, a thioacetate, or a thioformate), analkoxyl, a phosphoryl, a phosphate, a phosphonate, a phosphinate, anamino, an amido, an amidine, an imine, a cyano, a nitro, an azido, asulfhydryl, an alkylthio, a sulfate, a sulfonate, a sulfamoyl, asulfonamido, a sulfonyl, a heterocyclyl, an aralkyl, or an aromatic orheteroaromatic moiety. It will be understood by those skilled in the artthat the moieties substituted on the hydrocarbon chain can themselves besubstituted, if appropriate.

The term “C_(x-y) alkyl” refers to unsubstituted saturated hydrocarbongroups, including straight-chain alkyl and branched-chain alkyl groupsthat contain from x to y carbons in the chain. For example, C₁₋₆ alkylis an alkyl group having one to six carbons.

The term “alkoxy” refers to an alkyl group having an oxygen attachedthereto. Representative alkoxy groups include methoxy, ethoxy, propoxy,tert-butoxy and the like. An “ether” is two hydrocarbons covalentlylinked by an oxygen. Accordingly, the substituent of an alkyl thatrenders that alkyl an ether is or resembles an alkoxy.

The term “heteroaryl” includes substituted or unsubstituted aromatic 5-to 7-membered ring structures, more preferably 5- to 6-membered rings,whose ring structures include one to four heteroatoms. The term“heteroaryl” also includes polycyclic ring systems having two or morecyclic rings in which two or more carbons are common to two adjoiningrings wherein at least one of the rings is heteroaromatic, e.g., theother cyclic rings can be cycloalkyls, cycloalkenyls, cycloalkynyls,aryls, heteroaryls, and/or heterocyclyls. Heteroaryl groups include, forexample, pyrrole, furan, thiophene, imidazole, oxazole, thiazole,triazole, pyrazole, pyridine, pyrazine, pyridazine and pyrimidine, andthe like.

The terms “heterocyclyl” or “heterocyclic group” refer to substituted orunsubstituted non-aromatic 3- to 10-membered ring structures, morepreferably 3- to 7-membered rings, whose ring structures include one tofour heteroatoms. The terms “heterocyclyl” or “heterocyclic group” alsoinclude polycyclic ring systems having two or more cyclic rings in whichtwo or more carbons are common to two adjoining rings wherein at leastone of the rings is heterocyclic, e.g., the other cyclic rings can becycloalkyls, cycloalkenyls, cycloalkynyls, aryls, heteroaryls, and/orheterocyclyls. Heterocyclyl groups include, for example, piperidine,piperazine, pyrrolidine, morpholine, lactones, lactams, and the like.

The term “urea” as used herein includes a moiety that can be representedby the general formula:

wherein R^(c), R^(d), and R^(e) each independently represent a hydrogen,an alkyl, an alkenyl, —(CH₂)_(m)—R^(f), or R^(c) and R^(d) takentogether with the N atom to which they are attached complete aheterocycle having from 4 to 8 atoms in the ring structure; R^(f)represents an aryl, a cycloalkyl, a cycloalkenyl, a heterocyclyl or apolycyclyl; and m is zero or an integer from 1 to 8. In preferredembodiments, only one of R^(c) and R^(d) is a carbonyl, e.g., R^(c),R^(d), and the nitrogen together do not form an imide. In even morepreferred embodiments, R^(c) and R^(d) (and optionally R^(e)) eachindependently represent a hydrogen, an alkyl, an alkenyl, or—(CH₂)_(m)—R^(f).

As used herein, a “protecting group” is a moiety that masks the chemicalreactivity of a functional group during one or more reactions. In anillustrative example, an oxygen protecting group such as 4-methoxybenzyl(PMB) can be introduced at one step to mask the chemical reactivity ofan —OH function on a carboxylic acid or an alcohol during one or morereactions then removed under acidic conditions to allow the —OH group toundergo reaction in the next step. A protecting group can be any oneknown in the art, such as those described in Wuts, P. G. M.; Greene, T.W. Greene's Protective Groups in Organic Synthesis, 4^(th) ed; JohnWiley & Sons: Hoboken, N.J., 2007.

In some embodiments, the oxygen protecting group is a base-labile oxygenprotecting group (i.e., one that is removed under basic conditions),such as a methyl group when used as an ester to protect a carboxylicacid (i.e., —COOH). In some embodiments, the oxygen protecting group isan acid-labile oxygen protecting group (i.e., one that is removed underacidic conditions), such as tert-butyldimethylsilyl (i.e., TBDMS),tert-butyl, 4-methoxybenzyl (i.e., PMB, MPM), 2-methoxybenzyl, ortriphenylmethyl (i.e., trityl or Tr). In some embodiments, the oxygenprotecting group is an oxidation-reduction sensitive oxygen protectinggroup, such as a benzyl ether which is removed under oxidative orreductive conditions, e.g., catalytic hydrogenation conditions.

In some embodiments, the nitrogen protecting group is a base-labilenitrogen protecting group (i.e., one that is removed under basicconditions), such as 9-fluorenylmethyl carbamate (Fmoc). In someembodiments, the nitrogen protecting group is an acid-labile nitrogenprotecting group (i.e., one that is removed under acid conditions), suchas tert-butyl, tert-butoxycarbonyl (i.e., tert-butyloxycarbonyl, Boc, orBOC), 2-trimethylsilylethoxycarbonyl (i.e., Teoc), or triphenylmethyl.In some embodiments, the nitrogen protecting group is anoxidation-reduction sensitive nitrogen protecting group, such as abenzyl or benzyloxycarbonyl, which can be removed under oxidative orreductive conditions, e.g., under catalytic hydrogenation conditions.

Pharmaceutically acceptable salts are known to those of skill in theart. Pharmaceutically acceptable salts can be prepared in situ duringthe final isolation and purification of the compound, or by separatelycontacting a purified compound with a suitable organic or inorganicacid, and isolating the salt thus formed. Representative salts includethe hydrobromide, hydrochloride, hydrogen iodide, sulfate, bisulfate,phosphate, nitrate, acetate, valerate, oleate, palmitate, stearate,laurate, benzoate, lactate, tosylate, citrate, maleate, fumarate,succinate, tartrate, naphthylate, mesylate, edisylate, glucoheptonate,lactobionate, laurylsulfonate salts, and amino acid salts, and the like.See, for example, Berge et al. 1977, “Pharmaceutical Salts,” J. Pharm.Sci. 66: 1-19.

6.2. Crystalline Forms of a Compound of Formula (III′)

Provided herein are crystalline forms of a compound of formula (III′),processes of making crystalline forms of a compound of formula (III′),and use of said forms in the synthesis of antibacterial cephalosporins(e.g., ceftolozane).

Disclosed herein is a crystalline form of a compound of formula (III′):

wherein

X is Cl, Br, or I; and

R¹ and R² are each independently an oxygen protecting group.

In some embodiments, X is Cl.

In some embodiments, R¹ is an acid-labile oxygen protecting group. Insome embodiments, R¹ is selected from the group consisting of:tert-butyldimethylsilyl, tert-butyl, 4-methoxybenzyl, 2-methoxybenzyl,or triphenylmethyl. In some embodiments, R¹ is 4-methoxybenzyl.

In some embodiments, R² is an acid-labile oxygen protecting group. Insome embodiments, R² is selected from the group consisting of:tert-butyldimethylsilyl, tert-butyl, 4-methoxybenzyl, 2-methoxybenzyl,or triphenylmethyl. In some embodiments, R² is tert-butyl.

In some embodiments, R¹ and R² are each independently an acid-labileoxygen protecting group. In some embodiments, R¹ and R² are eachindependently tert-butyldimethylsilyl, tert-butyl, 4-methoxybenzyl,2-methoxybenzyl, or triphenylmethyl. In some embodiments, R¹ is4-methoxybenzyl, and R² is tert-butyl.

In some embodiments, the crystalline form of a compound of formula(III′) is a solvate. In some embodiments, the crystalline form is asolvate of an aromatic solvent. In some embodiments, the crystallineform is a solvate of toluene, xylene, ethylbenzene, benzene, or cumene,or mixtures thereof, preferably toluene. When crystalline forms aresolvated, they can exist in varying molar ratios of compound to solventwithin the unit cell. In some embodiments, the molar ratio of a compoundof formula (III′) to solvent is in a range of from about 1:3 to about4:1, such as about 1:2 to 3:1, about 1:2 to 2:1, about 1:2 to 1:1, about1:1 to 3:1, or about 1:1 to 2:1. In some embodiments, the molar ratio ofa compound of formula (III′) to solvent is about 1:3, about 1:2, about1:1, about 1.5:1, about 2:1, about 2.5:1, about 3:1, or about 4:1. In apreferred embodiment, the molar ratio of a compound of formula (III′) tosolvent is about 1:1.

In some embodiments, the crystalline form is not solvated. In someembodiments, the crystalline form is substantially free of solvent.

In some embodiments, the crystalline form of a compound of formula(III′) has the structure of a compound of formula (III) (“compound(III)”):

In some embodiments, the crystalline form of a compound of formula(III′), e.g., compound (III), has an X-ray powder diffraction patterncomprising one or more, two or more, three or more, four or more, orfive or more characteristic peaks expressed in degrees 2θ at 6.1+0.2,12.1±0.2, 13.1±0.2, 18.5±0.2, and 24.3±0.2. In some embodiments, thecrystalline form has an XRPD pattern comprising the peaks as shown inTable 1. In some embodiments, the X-ray powder diffraction pattern issubstantially as shown in FIG. 3A.

In some embodiments, the crystalline form of a compound of formula(III′), e.g., compound (III), has an X-ray powder diffraction patterncomprising one or more, two or more, three or more, four or more, orfive or more characteristic peaks expressed in degrees 2θ at 7.3±0.2,10.0±0.2, 11.6±0.2, 17.7±0.2, and 24.6±0.2. In some embodiments, thecrystalline form has an XRPD pattern comprising the peaks as shown inTable 2A. In some embodiments, the X-ray powder diffraction pattern issubstantially as shown in FIG. 3B.

In some embodiments, the crystalline form of a compound of formula(III′), e.g., compound (III), has an X-ray powder diffraction patterncomprising one or more, two or more, three or more, four or more, orfive or more characteristic peaks expressed in degrees 2θ at 7.1 -0.2,12.4±0.2, 18.5±0.2, 19.3±0.2, and 25.5±0.2. In some embodiments, thecrystalline form has an XRPD pattern comprising the peaks as shown inTable 2B. In some embodiments, the X-ray powder diffraction pattern issubstantially as shown in FIG. 3D.

In some embodiments, the crystalline form of a compound of formula(III′), e.g., compound (III), has a thermogravimetric analysisthermogram substantially as shown in FIG. 4.

In some embodiments, the crystalline form of a compound of formula(III′), e.g., compound (III), has a differential scanning calorimetrythermogram substantially as shown in FIG. 5.

6.3. Crystalline Forms of TATD-CLE

Provided herein are crystalline forms of compound (III), e.g., a toluenesolvate of compound (III) (“TATD-CLE toluene solvate”), processes ofmaking crystalline forms (such as toluene solvates) of compound (III),and use of said forms in the synthesis of antibacterial cephalosporinssuch as ceftolozane. The toluene solvates of TATD-CLE are advantageousin that they can be obtained in crystalline form, making themparticularly suitable for use in the manufacture of pharmaceuticallyimportant cephalosporins, such as ceftolozane and salts of ceftolozane(e.g., compounds (Vb) or (VI)).

Provided herein is a toluene solvate of compound (III):

The toluene solvate of compound (III) (“TATD-CLE”) can be crystalline.

As illustrated in FIG. 3A and FIG. 3B, at least two crystalline formshave been characterized by X-Ray Powder Diffraction (XRPD), e.g,TATD-CLE form 1 (FIG. 3A) and TATD-CLE form 2 (FIG. 3B). TATD-CLE form 1can be converted to yet another TATD-CLE form 2 by heating to about 108°C. TATD-CLE form 2 was formed by heating in a differential scanningcalorimeter. This sample was taken from the calorimeter and subsequentlyanalyzed by XRPD to indicate the formation of crystalline TATD-CLE form2.

Additionally, another crystalline form of a compound of formula (III′),TATD-CLE form 3, is formed upon heating as shown in the VT-XRPD in FIG.3C. As shown in FIG. 3D, TATD-CLE form 3 is produced from TATD-CLE form1 upon heating to 110° C. in the X-ray powder diffractometer.

In one embodiment, TATD-CLE form 1 can be identified by an XRPD patterncomprising one or more, two or more, three or more, four or more, orfive or more characteristic peaks expressed in degrees 2θ at about 6.1,about 12.1, about 13.1, about 18.5, and about 24.3. In anotherembodiment, TATD-CLE form 1 can be identified by an XRPD patterncomprising one or more, two or more, three or more, four or more, orfive or more characteristic peaks expressed in degrees 2θ at 6.1±0.2,12.1±0.2, 13.1+0.2, 18.5±0.2, and 24.3±0.2. In some embodiments, thecrystalline TATD-CLE form 1 has an XRPD pattern comprising the peaks asshown in Table 1. In some embodiments, the crystalline TATD-CLE form 1has an XRPD pattern substantially as shown in FIG. 3A.

TATD-CLE form 2 can be identified by an XRPD pattern comprising one ormore, two or more, three or more, four or more, or five or morecharacteristic peaks expressed in degrees 2θ at about 7.3, about 10.0,about 11.6, about 17.7, and about 24.6. In another embodiment, TATD-CLEform 2 can be identified by an XRPD pattern comprising one or more, twoor more, three or more, four or more, or five or more characteristicpeaks expressed in degrees 2θ at 7.3+0.2, 10.0±0.2, 11.6±0.2, 17.7±0.2,and 24.6±0.2. In some embodiments, the crystalline TATD-CLE form 2 hasan XRPD pattern comprising the peaks as shown in Table 2A. In someembodiments, the crystalline TATD-CLE form 2 has an XRPD patternsubstantially as shown in FIG. 3B.

TATD-CLE form 3 can be identified by an XRPD pattern comprising one ormore, two or more, three or more, four or more, or five or morecharacteristic peaks expressed in degrees 2θ at about 7.1, about 12.4,about 18.5, about 19.3, and about 25.5. In another embodiment, TATD-CLEform 3 can be identified by an XRPD pattern comprising one or more, twoor more, three or more, four or more, or five or more characteristicpeaks expressed in degrees 2θ at 7.1±0.2, 12.4±0.2, 18.5±0.2, 19.3±0.2,and 25.5+0.2. In some embodiments, the crystalline TATD-CLE form 3 hasan XRPD pattern comprising the peaks as shown in Table 2B. In someembodiments, the crystalline TATD-CLE form 3 has an XRPD patternsubstantially as shown in FIG. 3D.

In an embodiment, the toluene solvate of compound (III), i.e., TATD-CLEform 1, is characterized by an XRPD pattern having one or more, two ormore, three or more, four or more, or five or more peaks atsubstantially the angles (2θ±0.2) of Table 1. In another embodiment,TATD-CLE form 1 is characterized by an X-ray powder diffraction patternthat is substantially the same as the spectra of FIG. 3A.

In an embodiment, the crystalline form of compound (III), i.e., TATD-CLEform 2, is characterized by an X-ray powder diffraction pattern havingone or more, two or more, three or more, four or more, or five peaks atsubstantially the angles (2θ±0.2) of Table 2A. In another embodiment,TATD-CLE form 2 is characterized by an X-ray powder diffraction patternthat is substantially the same as the spectra of FIG. 3B.

In an embodiment, the crystalline form of compound (III), i.e., TATD-CLEform 3, is characterized by an X-ray powder diffraction pattern havingone or more, two or more, three or more, four or more, or five peaks atsubstantially the angles (2θ±0.2) of Table 2B. In another embodiment,TATD-CLE form 3 is characterized by an X-ray powder diffraction patternthat is substantially the same as the spectra of FIG. 3D.

In another aspect, provided herein is a composition comprising acrystalline form of a compound of formula (III′), e.g., TATD-CLE toluenesolvate. In an embodiment, the composition comprises TATD-CLE in one ormore solid forms (e.g., TATD-CLE form 1 and/or TATD-CLE form 2 and/orTATD-CLE form 3). In a further embodiment, the composition comprises acompound of formula (III′), e.g., compound (III), having an XRPD patterncomprising one or more characteristic peaks expressed in degrees 2θ atabout 6.1, about 12.1, about 13.1, about 18.5, and about 24.3 and/or acompound having an XRPD pattern comprising one or more characteristicpeaks expressed in degrees 2θ at about 7.3, about 10.0, about 11.6,about 17.7, and about 24.6 and/or a compound having an XRPD patterncomprising one or more characteristic peaks expressed in degrees 2θ atabout 7.1, about 12.4, about 18.5, about 19.3, and about 25.5. Inaddition, compositions comprising a compound of formula (III′), e.g.,compound (III), e.g., TATD-CLE form 1 and/or TATD-CLE form 2 and/orTATD-CLE form 3, can be identified by XRPD patterns with diffractions at20 indicated in Table 1 (TATD-CLE form 1), in Table 2A (TATD-CLE form2), and in Table 2B.

In another aspect, provided herein are compositions of crystallinecompound of a compound of formula (III′), e.g., compound (III),characterized by an X-ray powder diffraction pattern having peaks atsubstantially the same angles (20) as the spectra of FIG. 3C (i.e., amixture of TATD-CLE form 1 and TATD-CLE form 3).

TABLE 1 X-ray Powder Diffraction Peaks for TATD-CLE form 1 Angle 2-Theta° Relative Intensity % 6.105 99.7% 7.036 2.2% 12.076 9.1% 13.111 7.4%13.866 3.6% 14.210 1.7% 14.881 10.7% 15.577 3.1% 15.995 4.1% 16.319 2.9%16.627 3.4% 16.942 1.3% 17.182 1.1% 18.221 4.3% 18.490 15.0% 19.160 2.1%19.856 5.8% 20.183 13.9% 20.377 8.3% 21.080 2.8% 21.631 5.9% 22.134 7.6%22.529 3.3% 22.804 3.8% 23.533 1.2% 24.268 10.2% 25.147 4.1% 25.297 5.8%25.832 6.3% 26.124 2.3% 26.370 1.3% 26.874 1.3% 27.283 1.2% 27.733 1.1%29.946 1.5% 31.809 1.5% 36.153 1.1%

TABLE 2A X-ray Powder Diffraction Peaks for TATD-CLE form 2 Angle2-Theta ° Relative Intensity % 7.345 99.7% 9.977 11.8% 11.000 2.9%11.550 32.5% 12.954 5.9% 13.167 4.5% 13.447 2.8% 14.005 11.5% 14.72841.4% 15.386 20.0% 15.544 22.2% 16.028 20.7% 17.083 49.0% 17.651 39.9%18.358 6.0% 18.904 42.9% 19.656 99.9% 20.019 57.3% 20.368 8.3% 21.49038.9% 21.822 17.4% 21.951 25.7% 22.290 35.0% 22.757 58.6% 23.178 39.8%23.760 14.0% 24.643 29.4% 26.275 6.7% 26.631 9.7% 26.794 11.2% 27.12210.1% 27.513 14.8% 29.034 10.9% 29.647 10.9% 29.963 2.8% 30.222 13.4%30.545 3.4% 30.760 4.5% 31.414 4.7% 31.065 6.4% 32.726 8.5% 33.411 2.9%34.262 2.9% 34.880 4.5% 35.041 5.1% 35.712 8.3% 36.123 3.1% 36.358 4.8%37.142 2.4%

TABLE 2B X-ray Powder Diffraction Peaks for TATD-CLE form 3 Angle2-Theta ° Relative Intensity % 7.084 100.0% 11.672 33.0% 12.396 13.7%14.020 41.1% 14.938 19.4% 15.397 20.2% 16.051 14.0% 16.333 38.3% 16.88113.0% 17.552 18.8% 18.064 24.2% 18.523 76.6% 19.264 40.8% 20.359 36.9%20.889 14.8% 21.065 16.7% 21.189 18.5% 21.931 42.8% 22.813 33.5% 23.22035.7% 23.997 16.0% 24.632 23.1% 25.515 19.3% 27.246 12.3% 28.164 11.4%29.311 9.5% 31.819 11.4% 32.967 11.4%

FIG. 4 (TGA) and FIG. 5 (DSC) show TATD-CLE form 1 can be transformed byheating to around 108° C. A sample taken from the differential scanningcalorimeter and analyzed by XRPD showed TATD-CLE form 2. Melting ofTATD-CLE form 1 was observed at about 108° C., followed byrecrystallization at about 111° C. Melting of the second crystallineform was observed at about 122° C., followed by degradation at about150° C. Data from TGA are consistent with data observed from DSC.

FIG. 3C (VT-XRPD) shows formation of TATD-CLE form 3 from TATD-CLE form1 upon heating. FIG. 3D shows the XRPD of crystalline TATD-CLE form 3 at110° C. Table 2B describes the characteristic peaks of the crystal format 110° C. present in the VT-XRPD.

The level of solvent, e.g., toluene, in a crystalline form of a compoundof formula (III′), e.g., TATD-CLE toluene solvate (e.g., TATD-CLE form1), can be determined by residual solvent content analysis by gaschromatography (e.g., FIG. 7). In an embodiment, a TATD-CLE toluenesolvate contains between about 10% and about 15% toluene. In a furtherembodiment, a TATD-CLE toluene solvate contains about 11.70% of toluene.

6.4. Processes of Making a Crystalline Compound of Formula (III′)

Disclosed herein is a process of making a crystalline compound offormula (III′), e.g., compound (III). Crystallization methods includemethods to form a solid in a slow and controlled fashion to allow forordered formation of a crystal lattice. Such methods includesupersaturation of a solution comprising a compound to be crystallized.A number of methods known in the art can be applied to make acrystalline compound of formula (III′), including slow evaporation, slowcooling, vapor diffusion, and solvent diffusion.

In some embodiments, the process comprises the step of admixing anon-crystalline form of a compound of formula (III′), e.g., anon-crystalline form of compound (III), and an organic solvent to forman admixture, which comprises the crystalline form of a compound offormula (III′). In some cases, aging of the admixture affords a greateramount of the crystalline form.

A non-crystalline form of a compound as described herein, e.g., acompound of formula (III′), e.g., compound (III), can be in anynon-crystalline state. Non-limiting embodiments of non-crystalline formsinclude solutions, e.g., in a non-aromatic organic solvent such as ethylacetate or acetone; a non-crystalline solid, such as an amorphous form;or a semi-solid, such as a partially solvated solid.

In some embodiments, the organic solvent of the process comprises anantisolvent in which a compound of formula (III′), e.g., compound (III),is modestly soluble. In some embodiments, the antisolvent comprises ahydrocarbon solvent, such as pentane, hexane (e.g., n-hexane or amixture of hexane isomers), or heptane; an aromatic solvent, such astoluene, benzene, xylene (e.g., 1, 2-dimethylbenzene or a mixture ofxylene isomers, e.g., 1, 2-dimethylbenzene, 1, 3-dimethylbenzene, and/or1, 4-dimethylbenzene), cumene, or ethylbenzene; or mixtures thereof. Insome preferred embodiments, the antisolvent comprises toluene.

In some embodiments, the admixture of the process comprises one or moreadditional organic solvents, e.g., a second organic solvent, a thirdorganic solvent. In some embodiments, the one or more additional organicsolvents comprises a non-aromatic solvent. The one or more additionalorganic solvents can modify the characteristics of the antisolvent,e.g., by increasing the overall polarity of the resulting admixture. Insome embodiments, the non-aromatic solvent, such as ethyl acetate, isone in which the compound of formula (III′), e.g., compound (III), isdissolved prior to addition of the antisolvent.

Cooling a supersaturated solution can promote formation of crystallinecompounds, such as the crystalline form of a compound of formula (III′).In some embodiments, the admixture is cooled. In some embodiments, theadmixture is cooled to a range of from about −20° C. to about 25° C.,such as from about −15° C. to about 15° C., about −10° C. to about 15°C., about −5° C. to about 15° C., about 0° C. to about 15° C.; such asfrom about −15° C. to about 10° C., about −10° C. to about 10° C., about−5° C. to about 10° C., about 0° C. to about 10° C.; such as from about−15° C. to about 5° C., about −10° C. to about 5° C., or about −5° C. toabout 5° C. In some embodiments, the admixture is cooled to about −15°C., about −10° C., about −5° C., about 0° C., about 5° C., about 10° C.,about 15° C., or about 20° C.

Seed crystals can provide a surface on which the crystallization processcan begin. In some embodiments, the process comprises adding one or moreseed crystals. In some embodiments, the one or more seed crystalscomprise a compound of formula (III′), preferably the same compound offormula (III′) which is the subject of the crystallization process.

Isolation of the crystalline form can comprise decanting the supernatantliquid from the admixture, or filtering the admixture to obtain thecrystalline form. In some embodiments, the process comprises isolatingthe crystalline form of a compound of formula (III′), e.g., compound(III), by filtration. In some embodiments, the filtrate is washed withan amount of an organic solvent, e.g., the antisolvent.

In some embodiments, the process affords a crystalline compound offormula (III′) that has an XRPD pattern comprising one or more, two ormore, three or more, four or more, or five or more characteristic peaksexpressed in degrees 2θ at about 6.1, about 12.1, about 13.1, about18.5, and about 24.3. In some embodiments, the crystalline compound hasan XRPD pattern comprising one or more, two or more, three or more, fouror more, or five or more characteristic peaks expressed in degrees 2θ at6.1+0.2, 12.1±0.2, 13.1±0.2, 18.5±0.2, and 24.3±0.2. In someembodiments, the crystalline compound has an XRPD pattern comprising thepeaks as shown in Table 1. In some embodiments, the crystalline compoundhas an XRPD pattern substantially as shown in FIG. 3A.

In some embodiments, the process affords a crystalline compound offormula (III′) that has an XRPD pattern comprising one or more, two ormore, three or more, four or more, or five or more characteristic peaksexpressed in degrees 2θ at about 7.3, about 10.0, about 11.6, about17.7, and about 24.6, respectively. In some embodiments, the crystallinecompound has an XRPD pattern comprising one or more, two or more, threeor more, four or more, or five or more characteristic peaks expressed indegrees 2θ at 7.3±0.2, 10.0±0.2, 11.6±0.2, 17.7±0.2, and 24.6±0.2. Insome embodiments, the crystalline compound has an XRPD patterncomprising the peaks as shown in Table 2A. In some embodiments, thecrystalline compound has an XRPD pattern substantially as shown in FIG.3B.

In some embodiments, the process comprises converting a firstcrystalline form of a compound of formula (III′) to a second crystallineform of a compound of formula (III′). In an illustrative example, afirst crystalline form of a compound of formula (III′), e.g., a toluenesolvate of compound (III), e.g., TATD-CLE form 1, can be subjected toconditions, e.g., heated, to form a second crystalline form of acompound of formula (III′), e.g., TATD-CLE form 2. In some instances,heating a first crystal can lead to formation of a second crystal, e.g.,by partially or substantially desolvating a solvate form of a firstcrystalline form to make a second crystalline form. Other stressconditions, such as pressurizing a first crystalline form, may also leadto formation of a second crystalline form.

6.5. Processes of Making Crystalline TATD-CLE

The synthesis of TATD-CLE is known. For example, U.S. Pat. Nos.7,129,232 and 7,192,943 disclose a synthesis of ceftolozane andceftolozane-like compounds, respectively, from a compound of formula(III′), e.g., compound (III) (also referred herein as TATD-CLE). Thepreviously disclosed syntheses of TATD-CLE were based on working upreaction mixtures containing TATD-CLE with ethyl acetate or diisopropylether.

In contrast, disclosed herein is a synthesis of TATD-CLE using toluene.Use of toluene as a solvent for reaction isolation provides severalbenefits. First, the isolation with toluene provides a controlled androbust isolation process for TATD-CLE. Secondly, use of toluene in theisolation of TATD-CLE results in controlled particle size when comparedto a isolation with diisopropyl ether, which produces TATD-CLE in largeparticles. Thirdly, small volumes of toluene solvent are used for thereaction isolation introducing an inert solvent like toluene, which willnot interfere with subsequent reaction steps (i.e., inert to subsequentreaction reagents and conditions). Additionally, diisopropyl ether andrelated ethereal solvents can form peroxides upon storage that can beexplosive. Finally, the flash point of toluene is 6° C., as compared tothe flash point of diisopropyl ether of about −28° C. The higher flashpoint of toluene reduces the risk of fire. Thus, the use of toluene notonly offers advantages with respect to the process of making TATD-CLE,but also results in unexpectedly stable, crystalline forms of TATD-CLE.

Also disclosed herein is a process to prepare a crystalline form of acompound of formula (III′), e.g., a crystalline toluene solvate ofcompound (III). The crystalline form of a compound confers a number ofbenefits, including enhanced purity of the compound, ease of compoundisolation (e.g., ease of filtering), and enhanced stability as comparedwith a non-crystalline form (e.g., to degradation by, e.g., heat, light,radiation, undesirable chemical side reactions), which allows forlong-term storage.

As a non-limiting example, forms of a crystalline compound of formula(III′), e.g., TATD-CLE toluene solvate, can be prepared from thereaction illustrated in FIG. 2, wherein ACLE-HCl, a compound of formula(II), (also known as(6R,7R)-3-(chloromethyl)-2-(((4-methoxybenzyl)oxy)carbonyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-aminiumchloride with CAS No.: 113479-65-5) is admixed, e.g., reacted, withTATD-Ms, a compound of formula (Ib). This conversion of TATD-Ms toTATD-CLE can be carried out in the presence of triethylamine. In anembodiment, the reaction of ACLE-HCl, a compound of formula (II), withTATD-Ms, a compound of formula (Ib), is carried out over about 1 hour ofreaction time in solution, preferably in a biphasic solvent mixture suchas ethyl acetate and water, at a temperature of from about 0° C. toabout 7° C. and pH of from about 2 to about 4. In an embodiment, the pHis adjusted by using triethylamine (Et₃N).

In an embodiment, the process of obtaining the toluene solvate ofTATD-CLE further comprises obtaining compound (III) by adding sodiumchloride solution to the reaction mixture of compound (II) and compound(Ib), followed by separation of the aqueous layer from the organic layer(e.g., the ethyl acetate layer) and further washing the organic layerwith sodium chloride solution.

Formation of the crystalline compound of formula (III′), e.g., TATD-CLE,e.g., the toluene solvate, can comprise extracting TATD-CLE from thereaction mixture with a first organic solvent and concentrating thefirst organic extract, followed by addition of an antisolvent, e.g.,toluene, to the first organic extract. Isolation of the solids byfiltering, and washing the filtered solids with antisolvent, e.g.,toluene, can yield the crystalline TATD-CLE, e.g., toluene solvate, as asolid after drying. In an embodiment, the first organic solventcomprises ethyl acetate.

FIG. 2 and Table 3 provide exemplary ranges of values for variousprocess parameters (Step 4, Step 5, Step 6) for the manufacturing ofsolid forms of TATD-CLE, e.g., the toluene solvate, as well as preferredranges and values for each process parameter.

TABLE 3 Process Parameters for the Formation and Isolation of TATD-CLESolid Forms Normal Preferred Operating Target Process Parameter RangeRange Value (Step 4) Process Parameters for the Reaction to FormTATD-CLE Water (vol., L/kg) ≧2 2 to 5 3 EtOAc (vol., L/kg) ≧2 2 to 5 3Reaction pH 2.0 to 5.0 2.0 to 4.0 3.5 Reaction temperature (° C.)  0 to10 0 to 7 2 (Step 5) Process Parameters for the Quench of TATD-CLETemperature of quench (° C.) −10 to 20  −5 to 5  0 NaCl (wt. equiv) 0.0to 0.2 0.05 to 0.15 0.10 NaCl solution concentration (w/v %)  5 to 25 18to 22 20 NaCl solution (vol., L/kg) ≧2 2 to 4 3 (Step 6) ProcessParameters for the Isolation of TATD-CLE Distillation temperature (° C.)≦30  15 to 25 20 Batch volume after concentration 2.5 to 3.5 2.5 to 3.53.0 (vol., L/kg) Temperature before cooling (° C.) 10 to 30 18 to 22 201^(st) toluene portion (vol., L/kg) 0.5 to 2.0 0.5 to 1.5 1.0 Seedamount (weight %) 0.5 to 8.0 3.0 to 5.0 4.0 Batch stirring time afterseed (h) 1 to 8 2 to 4 3 2^(nd) toluene portion (vol., L/kg)  6 to 16  8to 10 9 2^(nd) toluene addition rate (vol./h) 0.3 to 3   0.4 to 1   0.5Batch stirring time before cooling ≧1 3 to 5 4 (h) Temperature duringcooling (° C.) −10 to 30   0 to 10 1 Toluene product wash ≧1  2 to 10 8(vol., L/kg)

A composition comprising a crystalline compound of formula (III′), e.g.,TATD-CLE toluene solvate, can be obtained by a process comprising theconditions described in Table 3: (Step 4) Process Parameters for theReaction to Form TATD-CLE; (Step 5) Process Parameters for the Quench ofTATD-CLE; and (Step 6) Process Parameters for the Isolation of TATD-CLE.

The reaction to form TATD-CLE (Step 4, Table 3) comprises the steps of:(a) forming a reaction mixture comprising ACLE-HCl, water (from about 2to about 5 volumes), and EtOAc (from about 2 to about 5 volumes); (b)adjusting the pH of the reaction mixture to between about 2 and about 4with triethylamine (Et₃N); (c) adding compound (Ib) (TATD-Ms) in EtOActo the reaction mixture, while maintaining a pH of between about 2 andabout 4 with additional Et₃N; (d) agitating the reaction mixture untilthe reaction is complete (i.e., until residual levels of ACLE are ≦2.2%(area % on HPLC) with respect to TATD-CLE.

In an embodiment, the time sufficient for completion of the reaction isbetween about 0.5 and about 1 hour. In another embodiment, a reactiontemperature of from about 0 to about 7° C. is maintained throughout thereaction.

The procedure to quench the reaction resulting in TATD-CLE (Step 5,Table 3) comprises the steps of: (a) adjusting the reaction mixture to atemperature of from about −5 to about 5° C.; (b) adding from about 0.05to about 0.15 weight equivalents of solid NaCl to the reaction mixture,then agitating and allowing separation of the mixture into an aqueousphase and an organic phase; (c) removing the aqueous phase and addingfrom about 18 to about 22 (w/v %) of aqueous NaCl to the remainingorganic phase; (d) adding from about 2 to about 4 volumes of NaClsolution to the mixture; (e) agitating the mixture, allowing the mixtureto separate into an aqueous phase and an organic phase, and isolatingthe organic phase.

The procedure to make the crystalline compound of compound (III), i.e.,“isolation of TATD-CLE solid form” shown in Table 3 above, comprises thesteps of one or more of the following: (a) concentrating the organicphase comprising the TATD-CLE (described above in Step 5(e)) to fromabout 2.5 to about 3.5 volumes under reduced pressure, at a temperaturebetween about 15 and about 25° C.; (b) (1) adding a first portion of anaromatic solvent, e.g., toluene, (from about 0.5 to about 1.5 volumes)and, optionally, (2) seeding with TATD-CLE (from about 3 to about 5weight %); (c) stirring the mixture of step (b) until nucleation (i.e.,further crystal formation) occurs; (d) (1) adding a second portion ofthe aromatic solvent, e.g., toluene, (from about 8 to about 10 volumes)at a rate of from about 0.4 to about 1 volumes/hour, (2) stirring theresulting suspension for from about 3 to about 5 hours, (3) optionally,cooling to from about 0 to about 10° C., and (4) isolating, e.g.,filtering, the precipitate (i.e., crystals); (e) washing the isolate,e.g., filter cake, with toluene (from about 2 to about 10 volumes), and(f) drying the isolate, e.g., filter cake, e.g., under reduced pressure.

In one embodiment, the filter cake (i.e., comprising the crystallinecompound of formula (III′)) is dried with a nitrogen flow until thewater content is ≦0.7% (IPC-3) and a LOD of ≦14.5% (IPC-4) denotingcompletion of the drying process. In another embodiment, a typicaldrying time is from about 8 to about 24 hours.

In one embodiment, the time sufficient for nucleation to occur is fromabout 2 to about 4 hours.

In an aspect, provided herein is process of making a toluene solvate ofcompound (III):

comprising the steps of:(a) admixing, e.g., reacting, compound (II):

with compound (Ib):

to form compound (III); and(b) admixing, e.g., extracting, compound (III) with an organic solventcomprising toluene; to obtain the toluene solvate of compound (III).

In an embodiment, the process further comprises the synthesis ofcompound (Ib):

by a process comprising the step of admixing, e.g., reacting, compound(I)

with methanesulfonyl chloride and potassium carbonate to yield compound(Ib).

In an aspect, provided herein is process of making a toluene solvate ofcompound (III):

comprising the steps of admixing compound (III) with an organic solventcomprising toluene to obtain the toluene solvate of compound (III).

In an embodiment, the toluene solvate is crystalline. In a furtherembodiment, the toluene solvate has an X-ray powder diffraction patterncomprising one or more, two or more, three or more, four or more, orfive or more characteristic peaks expressed in degrees 2θ at about 6.1,about 12.1, about 13.1, about 18.5, and about 24.3.

6.6. Processes Using a Crystalline Form of a Compound of Formula (III′)

Disclosed herein are processes for using a crystalline form of acompound of formula (III′), e.g., compound (III), which can be used tosynthesize other organic compounds.

In some embodiments, a process of making a compound of formula (V′), ora pharmaceutically acceptable salt thereof:

wherein R³ is selected from the group consisting of —COOH, —OH, analkoxy, a urea, a nitrogen-containing heteroaryl and anitrogen-containing heterocyclyl, wherein said alkoxy,nitrogen-containing heteroaryl and nitrogen-containing heterocyclyl areeach optionally substituted;comprises the step of admixing a crystalline form of a compound offormula (III′):

wherein X is Cl, Br, or I; and R¹ and R² are each independently anoxygen protecting group; with a nucleophile (R³-M), wherein M is H, ametal cation, a non-metal cation, or lone pair of electrons; to form acompound of formula (V′).

M can be a metal selected from, for example, alkali metals, alkalineearth metals, transition metals, and main group metals. For metalcations having a formal charge greater than one (e.g., 2), more than oneequivalent of R³ will be present in the nucleophile (e.g., (R³)₂M).

One skilled in the art will recognize that the formal charge of R³changes when a lone pair reacts to form a bond.

In some embodiments, M is H, a metal cation or a non-metal cation, e.g.,an ammonium cation, and R³ is selected from the group consisting of:

In some embodiments, M is H and R³-M is selected from the groupconsisting of

In some embodiments, R³ is a nitrogen-containing heteroaryl (i.e.,nitrogen-containing heteroaryl, or a heteroaryl containing at least onenitrogen in the ring). Nitrogen-containing heteroaryls include but arenot limited to pyrazoles, pyrroles, triazoles, pyridines, pyrimidines,thiazoles, and thiadiazoles, each of which can be optionallysubstituted. In some embodiments, R³ is a pyrazole, pyrrole, triazole,or pyridine, which are each optionally substituted. In some embodiments,R³ is a pyrazole or a pyridine, which are each optionally substituted.In some embodiments, R³ is an unsubstituted pyridine.

In some embodiments, R³-M is a compound of formula (IV′):

wherein R⁵ and R⁶ are each independently a nitrogen protecting group.

In some embodiments, R⁵ and R⁶ are each independently an acid-labilenitrogen protecting group. In some embodiments, R⁵ and R⁶ are eachindependently selected from the group consisting of: triphenylmethyl,tert-butoxycarbonyl, 2-trimethylsilylethoxycarbonyl, or triphenylmethyl.

In some embodiments, R⁵ is tert-butoxycarbonyl.

In some embodiments, R⁶ is triphenylmethyl.

In some embodiments, the compound of formula (IV′) has the structure ofcompound (IV):

In some preferred embodiments, a compound of formula (V′), or apharmaceutically acceptable salt thereof, has the structure of formula(V″):

wherein R⁵ and R⁶ are as defined herein, and A^(⊖) is a pharmaceuticallyacceptable anion.

In some embodiments, A^(⊖) is chloride, bromide, iodide, sulfate,bisulfate, tosylate (i.e., toluenesulfonate), mesylate (i.e.,methanesulfonate), edisylate, maleate, phosphate (e.g., monophosphate,biphosphate), ketoglutarate, trifluoroacetate, or triflate (i.e.,trifluoromethanesulfonate). In some embodiments, A^(⊖) is chloride,bromide, iodide, sulfate, bisulfate, tosylate, mesylate,trifluoroacetate, or triflate. In certain embodiments, A^(⊖) is selectedfrom chloride, acetate, trifluoroacetate and bisulfate (i.e., hydrogensulfate). In a particular embodiment, A^(⊖) is trifluoroacetate orbisulfate (i.e., HSO₄ ⁻). In certain embodiments, A^(⊖) istrifluoroacetate. In certain embodiments, A^(⊖) is bisulfate.

In some preferred embodiments, the compound of formula (V″) and/orformula (V′) has the structure of a compound of formula (V) (“compound(V)”):

In some embodiments, the process comprises the step of converting acompound of formula (V′), e.g., a compound of formula (V″) and/orcompound (V), to compound (VI′):

wherein A^(⊖) is as defined herein.

In some embodiments, the compound of formula (VI′) has the structure ofcompound (VI):

In some embodiments, the step of converting a compound of formula (V′)to a compound of formula (VI′), e.g., compound (VI), comprises exposing,e.g., contacting, the compound of formula (V′) to a strong acid, e.g.,trifluoroacetic acid.

In some embodiments, the process comprises the step of converting acompound of formula (VI′) to compound (VI), comprising contacting thecompound of formula (VI′) with sulfuric acid.

6.7. Crystalline TATD-CLE (e.g., Toluene Solvate) in the Synthesis ofCephalosporins

Ceftolozane can be obtained using methods described in U.S. Pat. Nos.7,129,232 and 7,192,943, as well as Toda et al., “Synthesis and SAR ofnovel parenteral anti-pseudomonal cephalosporins: Discovery ofFR264205,” Bioorganic & Medicinal Chemistry Letters, 18, 4849-4852(2008). Referring to FIGS. 1B and 1C, the synthesis of ceftolozane wasdisclosed from the starting material thiadiazolyl-oximinoacetic acidderivative (compound (I)), also referred to as TATD. Activation ofcarboxylic acid group of thiadiazolyl-oximinoacetic acid derivative(compound (I)) is carried out by methanesulfonyl chloride and potassiumcarbonate in a conventional solvent such as N, N-dimethylacetamide toyield the activated thiadiazolyl-oximinoacetic acid methane sulfonateester (Ib). The reaction of activated thiadiazolyl-oximinoacetic acidderivative (compound (Ib)) and 7-aminocephem compound (II) is disclosedto obtain compound (III), which can be further reacted with4-[(N-Boc-aminoethyl)carbamoylamino]-1-methyl-5-tritylaminopyrazole (IV)to obtain ceftolozane intermediate compound (V). The ceftolozaneintermediate (compound (V)) is universally deprotected using a mixtureof trifluoroacetic acid (TFA) and anisole to yield ceftolozane TFAintermediate compound (Vb), which is further crystallized with sulfuricacid to afford ceftolozane sulfate (compound (VI)).

The current invention offers several benefits to the synthesis ofceftolozane using TATD-CLE toluene solvate. For example, it provides acrystalline TATD-CLE product which contains low amounts of impuritiesdue to the crystalline nature of the compound.

In an aspect, provided herein is a process of making a compound offormula (V):

comprising the step of admixing, e.g., reacting, a toluene solvate ofcompound (III):

with compound (IV):

In an embodiment, the process further comprises the step of convertingcompound (V):

to compound (VI):

In one embodiment, the step of converting compound (V) to compound (VI)comprises exposing compound (V) to, e.g., contacting with, a strongacid, such as trifluoroacetic acid, sulfuric acid, formic acid,hydrochloric acid, or mixtures thereof. In some embodiments, the stepfurther comprises removing the excess strong acid. In some embodiments,the step comprises contacting with more than one strong acid,simultaneously (i.e., in a mixture) or consecutively (e.g.,trifluoroacetic acid, concentration of the solution, then contactingwith sulfuric acid).

In another aspect, provided herein is a cephalosporin compound, whereinthe compound is prepared from a toluene solvate of compound (III) viathe synthetic processes described herein (e.g., FIG. 1B).

6.8. Pharmaceutical Compositions

Ceftolozane (i.e., a compound of formula (Va), includingpharmaceutically acceptable salts thereof such as ceftolozane sulfate)can be formulated as a pharmaceutical composition. The pharmaceuticalcomposition can optionally further include a beta-lactamase inhibitorsuch as tazobactam. The ceftolozane can be obtained by processesdescribed herein. In particular, pharmaceutical compositions can beobtained by a process comprising the step of forming an aqueous solutioncontaining ceftolozane, and lyophilizing the aqueous solution to obtaina pharmaceutical composition. The aqueous solution may additionallycomprise excipients, stabilizers, pH adjusting additives (e.g., buffers)and the like. Non-limiting examples of these additives include sodiumchloride, citric acid and L-arginine. For example, the use of sodiumchloride can result in greater stability; L-arginine can be used toadjust pH and to increase the solubility of ceftolozane; and citric acidcan be used to prevent discoloration of the product, due to its abilityto chelate metal ions. In particular, the aqueous solution can includeceftolozane sulfate and additional components such as sodium chloride tostabilize the ceftolozane, and an alkalizing agent such as L-arginine toprovide a pH of about 5-7 prior to lyophilization. The pharmaceuticalcompositions can be lyophilized (freeze-dried) and stored as alyophilate for later reconstitution. Exemplary disclosures relating tolyophilization of pharmaceutical formulations include Konan et al., Int.J. Pharm. 2002, 233 (1-2), 293-52; Quintanar-Guerrero et al., J.Microencapsulation 1998, 15 (1), 107-119; Johnson et al., J.Pharmaceutical Sci. 2002, 91 (4), 914-922; and Tang et al.,Pharmaceutical Res. 2004, 21 (4), 191-200; the disclosures of which areincorporated herein by reference. As an alternative to lyophilization, apharmaceutical composition can be spray dried, or stored frozen and thenthawed, reconstituted, and diluted before administration.

Pharmaceutical compositions can include ceftolozane obtained by methodsdescribed herein, combined with a beta-lactamase inhibitor, such astazobactam (CAS#: 89786-04-9), avibactam (CAS#1192500-31-4), Sulbactam(CAS#68373-14-8) and/or clavulanate (CAS#58001-44-8). The beta lactamaseinhibitor can be included in a crystalline or amorphous form, such as alyophilized tazobactam or crystalline tazobactam (e.g., U.S. Pat. Nos.8,476,425 and 5,763,603) to obtain the pharmaceutical composition.

Pharmaceutical compositions comprising ceftolozane can be formulated totreat infections by parenteral administration (including subcutaneous,intramuscular, and intravenous) administration. In one particularembodiment, the pharmaceutical compositions described herein areformulated for administration by intravenous injection or infusion.Pharmaceutical antibiotic compositions can include ceftolozane sulfateand stabilizing amount of sodium chloride (e.g., 125 to 500 mg of sodiumchloride per 1,000 mg ceftolozane active) in a lyophilized unit dosageform (e.g., powder in a vial). The unit dosage form can be dissolvedwith a pharmaceutically acceptable carrier, and then intravenouslyadministered. In another aspect, pharmaceutical antibiotic compositionscan include ceftolozane sulfate obtained by a process comprising thesteps of lyophilizing an aqueous solution containing ceftolozane and astabilizing amount of sodium chloride, where the stabilizing amount ofsodium chloride is from about 125 to about 500 mg of sodium chloride per1,000 mg ceftolozane active in the aqueous solution prior tolyophilization.

6.9. Methods of Treatment

In one aspect, provided herein is a method for the treatment ofbacterial infections in a mammal, comprising administering to saidmammal a therapeutically effective amount of a pharmaceuticalcomposition comprising ceftolozane, or a pharmaceutically acceptablesalt thereof, prepared according to one or more of the methods describedherein. A method for the treatment of bacterial infections in a mammalcan comprise administering to said mammal a therapeutically effectiveamount of a pharmaceutical composition comprising ceftolozane sulfateand sodium chloride.

The pharmaceutical compositions can used in combination withmetronidazole for the treatment of complicated intra-abdominalinfections caused by the following Gram-negative and Gram-positivemicroorganisms such as: Escherichia coli (including strains producingCTX-M-14/15 ESBLs), Klebsiella pneumoniae (including strains producingCTX-M-15 ESBLs), Pseudomonas aeruginosa, Enterobacter cloacae,Klebsiella oxytoca, Proteus mirabilis, Bacteroides fragilis, Bacteroidesovatus, Bacteroides thetaiotaomicron, Bacteroides vulgatus,Streptococcus anginosus, Streptococcus constellatus, and Streptococcussalivarius.

The pharmaceutical compositions can used for the treatment ofcomplicated urinary tract infections, including pyelonephritis, with orwithout concurrent bacteremia, caused by the following Gram-negativemicroorganisms: Escherichia coli (including strains resistant tolevofloxacin and/or producing CTX-M-14/15 ESBLs), Klebsiella pneumoniae(including strains resistant to levofloxacin and/or producing CTX-M-15ESBLs), Proteus mirabilis, and Pseudomonas aeruginosa.

The recommended dosage regimen of pharmaceutical compositions comprisingceftolozane prepared by one or more methods disclosed herein, andtazobactam in an amount providing 1 g of ceftolozane active per 500 mgof tazobactam acid, is 1.5 g administered every 8 hours by intravenous(IV) infusion over 1 hour in patients ≧18 years of age. The duration oftherapy should be guided by the severity and site of infection and thepatient's clinical and bacteriological progress (e.g., every 8 hours for4-14 days for complicated Intra-Abdominal Infections and 7 days forComplicated Urinary Tract Infections, including Pyelonephritis).

7. EXAMPLES 7.1. Instrumentation and Methods

Other than Comparative Example 2, and unless otherwise indicated, thefollowing instrumentation and methods were used in the working Examplesdescribed herein. Comparative Example 2 was reported in U.S. Pat. No.7,192,943.

7.1.1. X-ray Powder Diffraction (XRPD)

X-ray Powder Diffraction experiments were performed on a Bruker D8diffractometer using Cu Kα radiation (40 kV, 40 mA), θ-2θ goniometer,primary and secondary Soller slits (2.5°), and a Ge monochromator andLynxeye detector (opening angle of 2.948°). Certified Corundum standard(NIST 1976) was used to check the performance of the instrument. Datacollection was performed by Diffrac.Suite Measurement Center v2.2.47.1and the collected data was analyzed and presented using Diffrac.EVA v2.0or v3.0.

Samples were tested under ambient conditions unless otherwise indicated.Approximately 5 mgs of each sample was flattened onto thezero-background silicon wafer, resulting in a smooth and flat surface.The scan type of coupled two theta/theta was used for the datacollection. The angular range used was 5 to 40°2θ, and the step size was0.020°2θ. The collection time was 0.1 s for each step. The geniometerradius was set at 280 mm. The sample rotation speed was 15 rpm, and theslit size used was 0.6 mm.

Reflections above 1% relative intensity are reported.

7.1.2. Variable Temperature (VT)-XRPD

Approximately 40 mg of the sample was placed in a Ni-coated sampleholder under ambient conditions. The sample was placed in Anton-Paar TTK450 chamber at 25° C. The temperature was controlled in-situ through themeasurement. The sample was heated from 30° C. to 170° C. at 2° C./min.XRPD data were collected at specific temperatures for 25 min per datacollection.

7.1.3. Thermal Analysis

Thermogravimetric Analysis (TGA) experiments were performed on a TAInstruments Discovery Series TGA. The calibration for temperature wascarried out using certified indium. Typically, 3-15 mg of a sample wasflattened into sealed aluminum pans. Data was acquired for samples withand without a pinhole. For samples with a pinhole, once crimped andsealed, the auto-sampler punched the lid of the sample with its internalpuncher right before analysis of the sample. Samples were heated at 20°C./min from 30° C. to 400° C. Dry nitrogen was purged into the systemduring the experiment at a rate of 50 mL/min. The software used tocontrol the instrument was TRIOS Explorer Software v5.3.0.75. TRIOSsoftware v2.40.1838 or v2.04.04563 was used for data analysis.

Differential Scanning Calorimetry (DSC) experiments were performed on aTA Instruments Q2000. The calibration for thermal capacity was carriedout using sapphire and the calibration for energy and temperature wascarried out using certified indium. Typically, 3-10 mg of a sample isflattened into sealed aluminum hermetic pans and the weight accuratelyrecorded. Data was acquired for samples with a pinhole in the lid.Samples were heated at 10° C./min from 25° C. to 350° C. Dry nitrogenwas purged into the system during the experiment at a rate of 50 mL/min.The software used to control the instrument is the Advantage for QSeries v2.9.0.396 and the Thermal Advantage v5.4.0. Data was analyzedusing the Universal Analysis v4.5A software.

7.1.4. Residual Solvent (Toluene) Analysis

TATD-CLE was analyzed for toluene by gas chromatography using an Agilent6890 gas chromatograph coupled with a flame-ionization detector.Headspace sampler Agilent 7694 was used to deliver the sample to the gaschromatography (GC) column. Details of the method are described below.

7.1.4.1. Standard Preparation

Linearity standard solutions of toluene were prepared in dimethylsulfoxide (2 mL total volume in headspace vial) with final standardamounts of 310.7 μg, 512.2 μg, 1280 μg, 1536 μg, 2049 μg, 4097 μg, and5122 μg. For the TATD-CLE sample size of approximately 10 mg, thesetoluene standard amounts are equivalent to w/iv 3.11%, 5.12%, 12.8%,15.36%, 20.49%, 40.97%, and 51.22%, respectively.

7.1.4.2. Sample Preparation

TATD-CLE solid was equilibrated to room temperature. Into a 20-mLheadspace vial, approximately 11 mg of TATD-CLE was accurately weighedand dissolved in 2 mL of dimethyl sulfoxide. Two additional samplesolutions were prepared in the identical fashion using separateweighings of TATD-CLE. Matrix spike samples were prepared in triplicatewith toluene spiking amount equivalent to 1294 μg in approximately 11 mgof TATD-CLE. These matrix spike samples were analyzed to demonstrateaccuracy of the method via determination of percent recovery.

Samples and standards were analyzed using the analytical methodconditions described in Table 4. Retention time for toluene under thesemethod conditions was approximately 12.8 minutes. Toluene peak areavalues corresponding to the linearity standard amounts were calibratedagainst these standard amounts to generate a calibration curve. Theamount of toluene in each of the three samples was determined usingequation 1. The weight by weight value of toluene relative to TATD-CLE(compound (III)) was determined using equation 2. Toluene content inTATD-CLE (compound (Ill)) was reported as the mean of the triplicatevalues.

$\begin{matrix}{{W_{Toluene}\mspace{14mu} ( {{in}\mspace{14mu} {µg}} )} = \frac{A_{Toluene} - b}{m}} & ( {{equation}\mspace{14mu} 1} )\end{matrix}$

Where,

-   -   W_(Toluene)=Amount of toluene in μg    -   A_(Toluene)=GC Peak area for toluene    -   b=intercept of the calibration curve    -   m=slope of the calibration curve

$\begin{matrix}{{{Toluene}\mspace{14mu} (\%)} = {\frac{W_{Toluene}}{W_{{TATD}\text{-}{CLE}}} \times \frac{1}{10000}}} & ( {{equation}\mspace{14mu} 2} )\end{matrix}$

Where,

-   -   W_(Toluene)=Amount of toluene (μg) determined using equation 1    -   W_(TATD-CLE)=Weight of TATD-CLE (g)    -   10000=factor to convert parts per million to percent

TABLE 4 Gas Chromatographic and Headspace Sampler Conditions Rxi-624 SilMS, 320 μm × 30 m, 1.8 μm GC Column thickness (Restek Corporation) GCParameters Carrier Gas Helium Flow Rate 0.9 mL/min Column Temperature(ramp) Initial  40° C.  6.00 min  40° C. 12.75 min 180° C. 15.00 min180° C. 18.00 min 300° C. Inlet Temperature 200° C. Detector Temperature240° C. Split Ratio 1:1 Injection Volume Full Loop (1 mL) Run Time 18minutes Detector Hydrogen 35 mL/min Flow Rates Make up 25 mL/min Air 350mL/min Headspace Sampler Parameters Vial Temperature 90° C. LoopTemperature 105° C. Transfer Line Temperature 125° C. GC Cycle Time 24min Thermostat Time 20 min Vial Pressure 0.75 bar Vial PressurizationTime 0.5 min Loop Fill Time 0.5 min Loop Equilibration Time 0.1 minInject Time 1.00 min Carrier Pressure 1.80 bar

7.1.4.3. System Suitability

A resolution solution comprising solvents methanol, ethanol, isobutanol,acetone, acetonitrile, methylene chloride, methyl t-butyl ether, ethylacetate, benzene, tetrahydrofuran, heptane, toluene, anisole,triethylamine, and pyridine, prepared in dimethyl sulfoxide diluent, wasinjected along with appropriate diluent blanks to demonstrate analytespecificity and resolution. Check standards were prepared at the 1553 μgtoluene level, which is the mid-point level of the calibration standardrange. These check standards were injected after every 10 injections.The sequence dataset was considered valid as the correlation coefficient(r²) of the calibration curve was greater than 0.995, the independentcheck standards agreed with initial calibration curve within ±10%, andthe percent recovery of toluene in the matrix spike samples were withinthe range of 90%-110%.

7.1.5. NMR Method

NMR experiments were performed on a 400 MHz Bruker Avance HD NMR(Nuclear Magnetic Resonance) Spectrometer equipped with a 5 mmPABBO/¹⁹F-¹H/D probe. The sample was prepared by dissolving 13 mg ofTATD-CLE toluene solvate compound (III) into 1 mL CDCl₃. The solutionwas transferred into a 5-mm NMR tube and the sample tube was insertedinto the magnet using a Sample Jet accessory. All experiments wereperformed at 298 K. Number of scans were 24.

Example 1: Preparation of (6R,7R)-4-methoxybenzyl-7-((Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(((I-(tert-butoxy)-2-methyl-1-oxopropan-2-yl)oxy)imino)acetamido)-3-(chloromethyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate(TATD-CLE)

Using the methods described herein, 98.7 kg of compound (I) wasconverted to 173.5 kg of compound (III), (TATD-CLE), an 80.1% yield. Theconversion of compound (I) to compound (Ib) was performed by admixing,e.g., reacting, compound (I) with methanesulfonyl chloride and potassiumcarbonate. The conversion of compound (Ib) to compound (III) wasperformed by reaction of compound of formula (Ib) with compound (II).The details of this synthesis procedure are disclosed below.

TATD (compound (I)) (98.7 kg) was dissolved in DMAc (620 L) at 0-5° C.and then methanesulfonyl chloride (68.5 kg) was added in 10 to 15minutes followed by potassium carbonate (41.3 kg). The reaction wasstirred at 3-7° C. for 1 hour then diluted with ethyl acetate (1,100 L)and washed with 1.7% concentrated HCl solution (600 L) and then a 10%sodium chloride solution (880 L). This organic solution was added to abiphasic mixture of compound (II) (115.0 kg), water (330 L) and ethylacetate (330 L) at 0-5° C. The pH of the reaction was continuouslymeasured and maintained at a pH of 3.2 to 3.8 using a solution oftriethylamine in ethyl acetate (1:1.9). The reaction was stirred for 30minutes and sodium chloride (10 kg) was added and stirred for anadditional 30 minutes. The lower aqueous layer was separated anddiscarded. The ethyl acetate solution was washed with 20% sodiumchloride solution (330 L). The organic solution was separated andconcentrated to 220 L, then toluene (1,145 L) and TATD-CLE seed (0.6 kg)was added. The solution was stirred for 10 hours at 22° C. then cooledto 3° C. and stirred for an additional 5 hours. The product was isolatedand dried to provide 173.5 kg of TATD-CLE form 1 as a white solid.

Calculation of the yield of the product was performed as shown below(from TATD)

-   -   98.7 kg TATD/330.36 MW TATD=0.2988 moles of TATD×681.18 MW        TATD-CLE=theoretical yield 203.54 kg    -   173.5 kg TATD-CLE/203.54 kg theoretical yield=85.2% yield (not        potency corrected)    -   148.17 kg TATD-CLE (using potency of 85.4% TATD-CLE)/203.54 kg        theoretical yield=84.7% yield (TATD-CLE potency corrected)        148.17 kg TATD-CLE/184.87 kg theoretical yield=80.1% yield (from        ACLE, potency corrected for ACLE and TATD-CLE).

Referring to FIG. 6, ¹H-NMR spectrum of TATD-CLE toluene solvate showedsignals for dimethyl protons, signals for tert-butyl protons andp-methoxybenzyl protons.

¹H NMR (400 MHz, CDCl₃) δ 7.72 (s, 2H, H-17), 7.38-7.31 (m, 2H, H-11),7.21-7.12 (m, 1H, H-14), 6.93-6.86 (m, 2H, H-12), 6.05 (dd, J=9.3, 5.0Hz, 1H, H-7), 5.26 (d, J=11.8 Hz, 1H, H-10), 5.21 (d, J=11.8 Hz, 1H,H-10), 5.05 (d, J=5.1 Hz, 1H, H-6), 4.54 (d, J=11.9 Hz, 1H, H-9), 4.46(d, J=11.8 Hz, 1H, H-9), 3.81 (s, 3H, H-13), 3.65 (d, J=18.3 Hz, 1H, H-2backward), 3.48 (d, J=18.3 Hz, 1H, H-2 forward), 1.60 (s, 6H, H-15),1.42 (s, 9H, H-16).

The NMR spectrum for TATD-CLE toluene solvate form 1 (FIG. 6) showed thepresence of toluene based on the signal at 6.8-7.4 ppm for aromaticprotons and signal at 2.30 ppm for methyl protons. Presence of the TATDmoiety was confirmed by signals of t-butyl group and two methyl groupsat 1.42 and 1.60 ppm, respectively. Presence of the p-methoxybenzyl ringwas confirmed based on the signal at 6.8-7.4 ppm for aromatic protons,signal at 3.81 ppm for methoxy group and signals at 5.27-5.19 ppm formethylene group. Presence of CLE ring was confirmed based on the signalat 6.05 and 5.05 ppm for protons on the four membered ring, signal at3.46-3.81 ppm and signal at 4.42-4.60 for methylene protons.

The level of toluene in TATD-CLE toluene solvate form 1 was determinedby residual solvent content analysis by gas chromatography (FIGS. 7 and8).

Example 2: Alternate Preparation of a Crystalline Form of Compound (III)

An alternate protocol is similar to that described in Example 1, withthe following modifications that are carried out according to theprocess parameters in Table 3 described above.

Subsequent to the reaction to form TATD-CLE, extraction with ethylacetate, and 20% sodium chloride solution wash as described in Example1, the combined organic extracts are concentrated to from about 2.5 toabout 3.5 volumes. Toluene (from about 0.5 to about 1.5 volumes, targetvalue of 1 volume) and seed crystals (from about 3.0 to about 5.0 weight%, target value of 4.0 weight %) are added. The solution is stirred forfrom about 2 to about 4 hours, then additional toluene (from about 8 toabout 10 volumes, target value of 9 volumes) is added at a rate of fromabout 0.4 to about 1 vol/h. The resulting solution is stirred for fromabout 3 to about 5 hours, then is cooled to from about 0 to about 10° C.(target value of 3° C.) for about 2 hours. The product solids arefiltered, and the filtered crystals washed with toluene (from about 2 toabout 10 volumes, target value of 8 volumes) to afford crystallineTATD-CLE toluene solvate form 1.

Yield from ACLE to TATD-CLE (potency corrected for ACLE and TATD-CLE) is88-92%.

Example 3: Comparative Synthesis of Compound (III) with Less than 80%Yield

U.S. Pat. No. 7,192,943, column 20, line numbers 5-35, discloses theconversion of compound (I) to compound (III) with a 75.4% yield. Thedetailed synthesis procedure from this second comparative example isdisclosed below.

To a solution of(Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-tert-butoxycarbonyl-1-methylethoxyimino)aceticacid compound (I) (319 g) in N,N-dimethylacetamide (1.5 L) were addedpotassium carbonate (113 g) and methanesulfonyl chloride (126 mL) underice-cooling. The mixture was stirred at 10° C. for 2 hours. The reactionmixture was added to a mixture of ethyl acetate and water. The organiclayer was washed with water and brine to give an activated acidsolution. Next, a suspension of 4-methoxybenzyl7β-amino-3-chloromethyl-3-cephem-4-carboxylate hydrochloride compound offormula (II) (300 g) in a mixture of water (1 L) and ethyl acetate (1 L)was adjusted to pH 6 with triethylamine under ice-cooling. To theresulting mixture was dropwise added the above obtained activated acidsolution at 10° C. under stirring. Stirring was continued at 5-10° C.for 1.5 hours keeping pH of the reaction mixture at 6 withtriethylamine. The organic layer was separated, washed with water andbrine, and evaporated in vacuo. The concentrate was poured intodiisopropyl ether (15 L), and the resulting precipitate was collected byfiltration and dried to give 4-methoxybenzyl7β-[(Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-tert-butoxycarbonyl-1-methylethoxyimino)acetamido]-3-chloromethyl-3-cephem-4-carboxylate,compound (III), (495.7 g), 75.4% yield.

8. EQUIVALENTS AND INCORPORATION BY REFERENCE

All publications, patents, patent applications and other documents citedin this application are hereby incorporated by reference in theirentireties for all purposes to the same extent as if each individualpublication, patent, patent application or other document wereindividually indicated to be incorporated by reference for all purposes.

While various specific embodiments have been illustrated and described,it will be appreciated that various changes can be made withoutdeparting from the spirit and scope of the invention(s).

1. A crystalline form of a compound of formula (III′):

wherein X is Cl, Br, or I; and R¹ and R² are each independently anoxygen protecting group.
 2. The crystalline form of claim 1, wherein R¹and R² are each independently tert-butyldimethylsilyl, tert-butyl,4-methoxybenzyl, 2-methoxybenzyl, or triphenylmethyl.
 3. The crystallineform of claim 1 wherein the compound of formula (III′) has the structureof compound (III):

wherein PMB is 4-methoxybenzyl.
 4. The crystalline form of claim 3 whichis a solvate of an aromatic solvent.
 5. The crystalline form of claim 4,wherein the aromatic solvent is toluene, xylene, ethylbenzene, benzene,cumene, or mixtures thereof.
 6. The crystalline form of claim 5, whichis a toluene solvate.
 7. The crystalline form of claim 4, which is inabout 1:1 molar ratio of compound (III) to solvent.
 8. The crystallineform of claim 1, wherein the form has an X-ray powder diffractionpattern comprising one or more characteristic peaks expressed in degrees2θ at about 6.1, about 12.1, about 13.1, about 18.5, and about 24.3. 9.The crystalline form of claim 1, wherein the form has an X-ray powderdiffraction pattern comprising one or more characteristic peaksexpressed in degrees 2θ at about 7.3, about 10.0, about 11.6, about17.7, and about 24.6.
 10. A process of making a crystalline form of acompound of formula (III′):

wherein X is Cl, Br, or I; and R¹ and R² are each independently anoxygen protecting group, comprising the step of admixing anon-crystalline form of a compound of formula (III′) and an aromaticsolvent to form an admixture comprising the crystalline form of acompound of formula (III′).
 11. The process of claim 10, wherein R¹ andR² are each independently tert-butyldimethylsilyl, tert-butyl,4-methoxybenzyl, 2-methoxybenzyl, or triphenylmethyl.
 12. The process ofclaim 10, wherein the compound of formula (III′) has the structure ofcompound (III):

wherein PMB is 4-methoxybenzyl.
 13. The process of claim 10, wherein thearomatic solvent comprises toluene.
 14. The process of claim 13, whereinthe crystalline form is a toluene solvate.
 15. The process of claim 13,wherein the crystalline form has an X-ray powder diffraction patterncomprising one or more characteristic peaks expressed in degrees 2θ atabout 6.1, about 12.1, about 13.1, about 18.5, and about 24.3.
 16. Theprocess of claim 10, further comprising the step of cooling theadmixture after the step of forming the admixture comprising thecrystalline form.
 17. The process of claim 16, wherein after the coolingstep the process further comprises the step of isolating the crystallineform of compound (III).
 18. A process of making a compound of formula(V″):

comprising admixing the crystalline form of claim 1 with a compound offormula (IV′):

wherein R¹ and R² are each independently an oxygen protecting group; R⁵and R⁶ are each independently a nitrogen protecting group; and A^(⊖) isa pharmaceutically acceptable anion.
 19. The process of claim 18,wherein R¹ and R² are each independently tert-butyldimethylsilyl,tert-butyl, 4-methoxybenzyl, 2-methoxybenzyl, or triphenylmethyl. 20.The process of claim 19, wherein R⁵ and R⁶ are each independentlytert-butyl, tert-butoxycarbonyl, 2-trimethylsilylethoxycarbonyl, ortriphenylmethyl.
 21. (canceled)
 22. (canceled)
 23. (canceled) 24.(canceled)